From 608818e67063c4a62e42a8a34216ffc09ac41242 Mon Sep 17 00:00:00 2001
From: Zach Pendleton <zachpendleton@gmail.com>
Date: Wed, 1 Oct 2014 16:30:42 -0600
Subject: [PATCH] add clustering support

if passed a cluster count through the CLUSTER environment
variable (e.g. CLUSTER=4 ./start.js), the server now runs
n processes on PORT, PORT+1, PORT+2, PORT+n.
---
 server.coffee |  8 +++++---
 start.js      | 17 +++++++++++++++--
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/server.coffee b/server.coffee
index 7cb52a3..e66dab9 100755
--- a/server.coffee
+++ b/server.coffee
@@ -4,6 +4,7 @@ Q = require 'q'
 _ = require 'underscore'
 express = require 'express'
 config = require 'config'
+cluster = require 'cluster'
 
 configWrapper = require './lib/configWrapper'
 load = require './lib/load'
@@ -22,13 +23,13 @@ loadConfig = (logger) ->
     load(MODULES.config, {config, logger})
   else
     configWrapper(config)
-    
+
 setCORSHeaders = (req, res, next) ->
   res.setHeader 'Access-Control-Allow-Origin', '*'
   res.setHeader 'Access-Control-Allow-Methods', 'POST'
   res.setHeader 'Access-Control-Max-Age', '604800'
   res.setHeader 'Access-Control-Allow-Credentials', 'true'
-  
+
   next()
 
 parser = (req, res, next) ->
@@ -53,7 +54,7 @@ parser = (req, res, next) ->
 
 loadApp = (logger, loadedConfig) ->
   app = express()
-     
+
   APP_ROOT = process.env.APP_ROOT ? loadedConfig.get('server.appRoot').get() ? ''
 
   moduleGroups = {}
@@ -109,6 +110,7 @@ loadApp = (logger, loadedConfig) ->
       res.send('OK\n')
 
     port = process.env.PORT ? loadedConfig.get('server.port').get() ? 5000
+    port = (port + cluster.worker.id - 1) if process.env.CLUSTER && cluster.isWorker
     app.listen(port)
 
     logger.log('Server listening on port %d in %s mode', port, app.settings.env)
diff --git a/start.js b/start.js
index e79ae8a..adf2071 100755
--- a/start.js
+++ b/start.js
@@ -1,4 +1,17 @@
 #!/usr/bin/env node
 
-require("coffee-script");
-require("./server.coffee");
+var cluster = require('cluster');
+
+if (process.env.CLUSTER) {
+  if (cluster.isMaster) {
+    for (var i=0; i < parseInt(process.env.CLUSTER); i++) {
+      cluster.fork();
+    }
+  } else {
+    require("coffee-script");
+    require("./server.coffee");
+  }
+} else {
+  require("coffee-script");
+  require("./server.coffee");
+}